Most women will get their menstrual period back within 6-18 months after they stop taking the Depo-Provera shot. Once you stop taking the (Depo-Provera) shot it continues to protect against pregnancy for just 3 more months. If you are sexually active and not using another form of birth control, there is a chance that you could be pregnant. Make an appointment with your health care provider to have a pregnancy test and discuss birth control options.